Problem: If $x \triangleleft y = 4x^{2}+y^{2}$ and $x \boxdot y = 4x-3$, find $-3 \boxdot (-3 \triangleleft 0)$.
Answer: We don't need to find $-3 \triangleleft 0$ because $x \boxdot y$ depends only on the left operand. Find $-3 \boxdot y$ $ -3 \boxdot y = (4)(-3)-3$ $ \hphantom{-3 \boxdot y} = -15$.